1 #include <linux/mutex.h> 2 #include <linux/socket.h> 3 #include <linux/skbuff.h> 4 #include <net/netlink.h> 5 #include <net/net_namespace.h> 6 #include <linux/module.h> 7 #include <net/sock.h> 8 #include <linux/kernel.h> 9 #include <linux/tcp.h> 10 #include <linux/workqueue.h> 11 12 #include <linux/inet_diag.h> 13 #include <linux/sock_diag.h> 14 15 static const struct sock_diag_handler *sock_diag_handlers[AF_MAX]; 16 static int (*inet_rcv_compat)(struct sk_buff *skb, struct nlmsghdr *nlh); 17 static DEFINE_MUTEX(sock_diag_table_mutex); 18 static struct workqueue_struct *broadcast_wq; 19 20 static u64 sock_gen_cookie(struct sock *sk) 21 { 22 while (1) { 23 u64 res = atomic64_read(&sk->sk_cookie); 24 25 if (res) 26 return res; 27 res = atomic64_inc_return(&sock_net(sk)->cookie_gen); 28 atomic64_cmpxchg(&sk->sk_cookie, 0, res); 29 } 30 } 31 32 int sock_diag_check_cookie(struct sock *sk, const __u32 *cookie) 33 { 34 u64 res; 35 36 if (cookie[0] == INET_DIAG_NOCOOKIE && cookie[1] == INET_DIAG_NOCOOKIE) 37 return 0; 38 39 res = sock_gen_cookie(sk); 40 if ((u32)res != cookie[0] || (u32)(res >> 32) != cookie[1]) 41 return -ESTALE; 42 43 return 0; 44 } 45 EXPORT_SYMBOL_GPL(sock_diag_check_cookie); 46 47 void sock_diag_save_cookie(struct sock *sk, __u32 *cookie) 48 { 49 u64 res = sock_gen_cookie(sk); 50 51 cookie[0] = (u32)res; 52 cookie[1] = (u32)(res >> 32); 53 } 54 EXPORT_SYMBOL_GPL(sock_diag_save_cookie); 55 56 int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attrtype) 57 { 58 u32 mem[SK_MEMINFO_VARS]; 59 60 mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk); 61 mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf; 62 mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk); 63 mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf; 64 mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc; 65 mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued; 66 mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc); 67 mem[SK_MEMINFO_BACKLOG] = sk->sk_backlog.len; 68 69 return nla_put(skb, attrtype, sizeof(mem), &mem); 70 } 71 EXPORT_SYMBOL_GPL(sock_diag_put_meminfo); 72 73 int sock_diag_put_filterinfo(bool may_report_filterinfo, struct sock *sk, 74 struct sk_buff *skb, int attrtype) 75 { 76 struct sock_fprog_kern *fprog; 77 struct sk_filter *filter; 78 struct nlattr *attr; 79 unsigned int flen; 80 int err = 0; 81 82 if (!may_report_filterinfo) { 83 nla_reserve(skb, attrtype, 0); 84 return 0; 85 } 86 87 rcu_read_lock(); 88 filter = rcu_dereference(sk->sk_filter); 89 if (!filter) 90 goto out; 91 92 fprog = filter->prog->orig_prog; 93 flen = bpf_classic_proglen(fprog); 94 95 attr = nla_reserve(skb, attrtype, flen); 96 if (attr == NULL) { 97 err = -EMSGSIZE; 98 goto out; 99 } 100 101 memcpy(nla_data(attr), fprog->filter, flen); 102 out: 103 rcu_read_unlock(); 104 return err; 105 } 106 EXPORT_SYMBOL(sock_diag_put_filterinfo); 107 108 struct broadcast_sk { 109 struct sock *sk; 110 struct work_struct work; 111 }; 112 113 static size_t sock_diag_nlmsg_size(void) 114 { 115 return NLMSG_ALIGN(sizeof(struct inet_diag_msg) 116 + nla_total_size(sizeof(u8)) /* INET_DIAG_PROTOCOL */ 117 + nla_total_size(sizeof(struct tcp_info))); /* INET_DIAG_INFO */ 118 } 119 120 static void sock_diag_broadcast_destroy_work(struct work_struct *work) 121 { 122 struct broadcast_sk *bsk = 123 container_of(work, struct broadcast_sk, work); 124 struct sock *sk = bsk->sk; 125 const struct sock_diag_handler *hndl; 126 struct sk_buff *skb; 127 const enum sknetlink_groups group = sock_diag_destroy_group(sk); 128 int err = -1; 129 130 WARN_ON(group == SKNLGRP_NONE); 131 132 skb = nlmsg_new(sock_diag_nlmsg_size(), GFP_KERNEL); 133 if (!skb) 134 goto out; 135 136 mutex_lock(&sock_diag_table_mutex); 137 hndl = sock_diag_handlers[sk->sk_family]; 138 if (hndl && hndl->get_info) 139 err = hndl->get_info(skb, sk); 140 mutex_unlock(&sock_diag_table_mutex); 141 142 if (!err) 143 nlmsg_multicast(sock_net(sk)->diag_nlsk, skb, 0, group, 144 GFP_KERNEL); 145 else 146 kfree_skb(skb); 147 out: 148 sk_destruct(sk); 149 kfree(bsk); 150 } 151 152 void sock_diag_broadcast_destroy(struct sock *sk) 153 { 154 /* Note, this function is often called from an interrupt context. */ 155 struct broadcast_sk *bsk = 156 kmalloc(sizeof(struct broadcast_sk), GFP_ATOMIC); 157 if (!bsk) 158 return sk_destruct(sk); 159 bsk->sk = sk; 160 INIT_WORK(&bsk->work, sock_diag_broadcast_destroy_work); 161 queue_work(broadcast_wq, &bsk->work); 162 } 163 164 void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh)) 165 { 166 mutex_lock(&sock_diag_table_mutex); 167 inet_rcv_compat = fn; 168 mutex_unlock(&sock_diag_table_mutex); 169 } 170 EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat); 171 172 void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh)) 173 { 174 mutex_lock(&sock_diag_table_mutex); 175 inet_rcv_compat = NULL; 176 mutex_unlock(&sock_diag_table_mutex); 177 } 178 EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat); 179 180 int sock_diag_register(const struct sock_diag_handler *hndl) 181 { 182 int err = 0; 183 184 if (hndl->family >= AF_MAX) 185 return -EINVAL; 186 187 mutex_lock(&sock_diag_table_mutex); 188 if (sock_diag_handlers[hndl->family]) 189 err = -EBUSY; 190 else 191 sock_diag_handlers[hndl->family] = hndl; 192 mutex_unlock(&sock_diag_table_mutex); 193 194 return err; 195 } 196 EXPORT_SYMBOL_GPL(sock_diag_register); 197 198 void sock_diag_unregister(const struct sock_diag_handler *hnld) 199 { 200 int family = hnld->family; 201 202 if (family >= AF_MAX) 203 return; 204 205 mutex_lock(&sock_diag_table_mutex); 206 BUG_ON(sock_diag_handlers[family] != hnld); 207 sock_diag_handlers[family] = NULL; 208 mutex_unlock(&sock_diag_table_mutex); 209 } 210 EXPORT_SYMBOL_GPL(sock_diag_unregister); 211 212 static int __sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) 213 { 214 int err; 215 struct sock_diag_req *req = nlmsg_data(nlh); 216 const struct sock_diag_handler *hndl; 217 218 if (nlmsg_len(nlh) < sizeof(*req)) 219 return -EINVAL; 220 221 if (req->sdiag_family >= AF_MAX) 222 return -EINVAL; 223 224 if (sock_diag_handlers[req->sdiag_family] == NULL) 225 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK, 226 NETLINK_SOCK_DIAG, req->sdiag_family); 227 228 mutex_lock(&sock_diag_table_mutex); 229 hndl = sock_diag_handlers[req->sdiag_family]; 230 if (hndl == NULL) 231 err = -ENOENT; 232 else 233 err = hndl->dump(skb, nlh); 234 mutex_unlock(&sock_diag_table_mutex); 235 236 return err; 237 } 238 239 static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) 240 { 241 int ret; 242 243 switch (nlh->nlmsg_type) { 244 case TCPDIAG_GETSOCK: 245 case DCCPDIAG_GETSOCK: 246 if (inet_rcv_compat == NULL) 247 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK, 248 NETLINK_SOCK_DIAG, AF_INET); 249 250 mutex_lock(&sock_diag_table_mutex); 251 if (inet_rcv_compat != NULL) 252 ret = inet_rcv_compat(skb, nlh); 253 else 254 ret = -EOPNOTSUPP; 255 mutex_unlock(&sock_diag_table_mutex); 256 257 return ret; 258 case SOCK_DIAG_BY_FAMILY: 259 return __sock_diag_rcv_msg(skb, nlh); 260 default: 261 return -EINVAL; 262 } 263 } 264 265 static DEFINE_MUTEX(sock_diag_mutex); 266 267 static void sock_diag_rcv(struct sk_buff *skb) 268 { 269 mutex_lock(&sock_diag_mutex); 270 netlink_rcv_skb(skb, &sock_diag_rcv_msg); 271 mutex_unlock(&sock_diag_mutex); 272 } 273 274 static int sock_diag_bind(struct net *net, int group) 275 { 276 switch (group) { 277 case SKNLGRP_INET_TCP_DESTROY: 278 case SKNLGRP_INET_UDP_DESTROY: 279 if (!sock_diag_handlers[AF_INET]) 280 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK, 281 NETLINK_SOCK_DIAG, AF_INET); 282 break; 283 case SKNLGRP_INET6_TCP_DESTROY: 284 case SKNLGRP_INET6_UDP_DESTROY: 285 if (!sock_diag_handlers[AF_INET6]) 286 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK, 287 NETLINK_SOCK_DIAG, AF_INET); 288 break; 289 } 290 return 0; 291 } 292 293 static int __net_init diag_net_init(struct net *net) 294 { 295 struct netlink_kernel_cfg cfg = { 296 .groups = SKNLGRP_MAX, 297 .input = sock_diag_rcv, 298 .bind = sock_diag_bind, 299 .flags = NL_CFG_F_NONROOT_RECV, 300 }; 301 302 net->diag_nlsk = netlink_kernel_create(net, NETLINK_SOCK_DIAG, &cfg); 303 return net->diag_nlsk == NULL ? -ENOMEM : 0; 304 } 305 306 static void __net_exit diag_net_exit(struct net *net) 307 { 308 netlink_kernel_release(net->diag_nlsk); 309 net->diag_nlsk = NULL; 310 } 311 312 static struct pernet_operations diag_net_ops = { 313 .init = diag_net_init, 314 .exit = diag_net_exit, 315 }; 316 317 static int __init sock_diag_init(void) 318 { 319 broadcast_wq = alloc_workqueue("sock_diag_events", 0, 0); 320 BUG_ON(!broadcast_wq); 321 return register_pernet_subsys(&diag_net_ops); 322 } 323 324 static void __exit sock_diag_exit(void) 325 { 326 unregister_pernet_subsys(&diag_net_ops); 327 destroy_workqueue(broadcast_wq); 328 } 329 330 module_init(sock_diag_init); 331 module_exit(sock_diag_exit); 332 MODULE_LICENSE("GPL"); 333 MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_SOCK_DIAG); 334